Before repainting a room I removed some shelves that were attached with wall anchors. I took the anchors out and patched with joint compound, layering until smooth. Then I sealed it with Zinsser Bullseye 123 primer. But when I painted, the texture difference with the patched area was very noticeable: it was as if I hadn't used any primer at all and the joint compound had just soaked up the paint: the patched area was smooth, without roller texture (3/8" roller). Should I try sealing again and repainting that area? Or just try a second coat over the patches?

Any idea why my garage wall is doing this? It's buckling along a seam at the bottom. I've been in the house almost 5 years. It was built in 2012. I could see that seam was cracked when I first moved in. It's gotten worse over the years. It got so bad that I was afraid that the baseplate was somehow buckling or there was water damage so I cut it open. It appears to just be the drywall but how/why? It's sitting atop a 4 1/2-foot block wall and is about 9 feet of drywall. The wall supports the second floor. My plan is to cut out where it's buckled and put a new sheet in, but not if it's going to continue to do that.